ROME — Vatican treasurer George Pell admitted Sunday that the Roman Catholic Church had “mucked things up” as he became the highest-ranking church official to testify on sexual abuse.

Giving evidence in front of abuse victims, the Australian cardinal said the organization reflected society as a whole and there was a “tendency to evil in the Catholic Church, too.”

"Too many people have committed suicide for these abuses"

He held up a bible as he took the oath in a Rome hotel room where he began to give evidence by video link to Australia's Royal Commission into Institutional Response to Child Sexual Abuse.

Pell was expected to clarify whether he knew that a number of priests were abusing children in the diocese near Melbourne where he served as a senior priest and vicar between 1973 and 1983. Among them was Australia's most notorious pedophile priest, Gerald Ridsdale, with whom Pell shared a house and who has been convicted for abusing more than 50 children over three decades.

Pell is not facing criminal charges, but his position as the Vatican’s economic secretary could become untenable if inquiry finds evidence that he either ignored or protected abusers. He is considered the third most powerful clergyman in the Vatican, after Pope Francis and the Secretary of State.

"I'm not here to defend the indefensible,” he said at the start of his testimony. “The Church has made enormous mistakes and is working to remedy those, but the Church in many places, certainly in Australia, has mucked things up, has let people down.”

He added: "Unfortunately, original sin is alive and well. There's tendency to evil in the Catholic Church too and sometimes it's better, sometimes it's worse but for good or for ill, the church follows the patterns of the societies in which it lives."

He also admitted that, in past decades, he was “very strongly inclined to accept” the word of priests who denied sex abuse. "They were very, very, very plausible allegations made by responsible people that were not followed up sufficiently” by the church, he added.

However, when pressed on specific situations involving particular priests some 40 years ago, Pell repeatedly said he couldn't recollect the incidents being put to him, at one point citing "a senior moment.”

He was testifying in Rome after saying he was too unwell to travel to the inquiry in Australia. A number of abuse victims traveled to Rome to see him give evidence in person — including pedophile Ridsdale’s nephew.

Dominic Ridsdale, 52, told NBC News: “[Pell] could have changed many things, he would have saved so many lives. Too many people have committed suicide for these abuses, and that’s why we are here today.”

Trish Charter, who says she was abused between the ages of four and eight at an orphanage run by the Sisters of Mercy, told Reuters: "He is an intelligent man, he is in such a high position, we all have our seniors moments but not on something like this.”